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Published on: December 11, 2017
Selection of patient for cardiac resynchronization therapy: role of QT corrected dispersion
Salvatore Timineri1, Massimiliano Mulè, Euglena Puzzangara
1Electrophysiology Unit, Cardiology Department, Ferrarotto Hospital, University of Catania, Catania, Italy. salvotimineri@hotmail.it
Insights
QT corrected dispersion (QTcD) can improve patient selection for cardiac resynchronization therapy (CRT). This ECG measure, alongside QRS duration, enhances the accuracy of identifying suitable candidates for CRT, improving treatment outcomes.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Diagnostics
Background:
- Cardiac resynchronization therapy (CRT) is recommended for heart failure patients, but 30-50% show no improvement.
- Current guidelines may not sufficiently identify all eligible CRT candidates.
- A more precise method for assessing CRT eligibility is needed.
Purpose of the Study:
- To evaluate the utility of QT corrected dispersion (QTcD) for selecting patients for CRT.
- To assess QTcD's effectiveness in predicting CRT response over a 12-month follow-up period.
Main Methods:
- 53 patients undergoing CRT were divided into two groups based on QTcD (>60 ms vs ≤60 ms).
- Baseline and 12-month follow-up assessments included NYHA class, 6-minute walk test, QTcD, QRS duration, and echocardiography.
- Changes in clinical and echocardiographic parameters were analyzed between groups.
Main Results:
- No significant baseline differences were observed between the QTcD groups.
- At 12 months, the QTcD > 60 ms group showed significantly worse outcomes: higher NYHA class, reduced 6-minute walk distance, lower LV ejection fraction, larger LV end-diastolic diameter, and increased LV dyssynchrony.
- These differences were statistically significant (P < 0.01).
Conclusions:
- QTc dispersion, in addition to QRS duration, may enhance electrocardiogram sensitivity for CRT patient selection.
- QTcD could serve as a valuable biomarker for identifying patients likely to benefit from CRT.
- Improved patient selection may lead to better CRT response rates.
Aims:
About 30 to 50% of patients undergoing cardiac resynchronization therapy (CRT) may not show clinical or echocardiographic improvement, despite fulfilling guidelines recommendations for CRT. For this reason, we need a more accurate method to assess CRT eligibility. The aims of this study were to verify, on a 12-month follow-up, the usefulness of QT corrected dispersion (QTcD) in a patient's selection for CRT.
Methods:
We stratified 53 patients who underwent CRT, into two groups based on the estimation of QTcD, that is, QTcD > 60 ms and QTcD ≤ 60 ms. In all patients were performed New York Heart Association (NYHA) class determination, six-minute walking test, QtcD, and QRS measurements, and complete echocardiographic assessment at 1, 3, 6, and 12 months after implantation.
Results:
At baseline, there were no significant differences in clinical, echocardiographic, and electrocardiographic parameters duration between two groups. At 12-month follow-up between the two groups, there were significant differences in NYHA (1.2 ± 0.4 vs 2 ± 0.6; P < 0.01), six-minute walking distance (422 ± 68 vs 364 ± 68; P < 0.01), left ventricular (LV) ejection fraction (34 ± 7% vs 28 ± 6%; P < 0.01), LV end-diastolic diameter (57 ± 7 vs 63 ± 8; P < 0.01), and LV intraventricular dyssynchrony (24 ± 14 vs 39 ± 23; P < 0.01).
Conclusion:
This study suggests that QTc dispersion in addition to QRS duration could improve the sensitivity of electrocardiogram in a patient's selection for CRT.
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